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HomeMy WebLinkAboutSDP 2017-0002; PACIFIC VISTA COMMERCE CENTER BUILDING PAD A; INTERIM SOILS REPORT; 2018-03-08GEOCON INCORPORATED GEOTECHNICAL ■ Project No. 06442-32-28A March 8, 2018 Ryan Companies 4275 Executive Square, Suite 370 La Jolla, California 92037 Attention: Mr. Ryan Soukup ENVIRONMENTAL ■ Subject: INTERIM REPORT OF TESTING AND OBSERVATION SERVICES DURING SITE GRADING PACIFIC VISTA COMMERCE CENTER MATERIALS °' (CARLSBAD OAKS NORTH BUSINESS PARK -LOT 23) BUILDING PAD 'A' CARLSBAD, CALIFORNIA Reference: Update Geotechnical Report, Pacific Vista Commerce Center (Carlsbad Oaks North Business Park-Lot 23), Carlsbad, California, prepared by Geocon Incorporated, dated June 14, 2017 (Project No. 06442-32-28). Dear Mr. Soukup: In accordance with your request, this interim report has been prepared to provide sufficient geotechnical information to obtain building permits for the commercial structures planned on Building Pad A. As of February 23, 2018, grading within the structure footprint of Building Pad A has been completed and the remaining earthwork for the project will be finished shortly. A final report of testing and observation services, including an As-Graded Geologic Map, will be prepared once the remainder of the grading has been completed. GENERAL The grading contractor for the project was FM & Sons. The project grading plans were prepared by SB&O Inc. titled Rough Grading Plans for: Pacific Vista Commerce Center, Sheets 1 through 23 Project No. SDP 2017-0002, Drawing No. 505-4A, undated. Recommendations for grading were provided in our report titled Update Geotechnical Report, Pacific Vista Commerce Center (Carlsbad Oaks North Business Park -Lot 23), Carlsbad, California, dated June 14, 2017 (Project No. 06442- 32-28). References to elevations and locations herein are based on as-graded survey information obtained from grade checkers' or surveyors' stakes in the field. Geocon Incorporated does not provide surveying 6960 Flanders Drive ■ San Diego, California 92121 -297 4 ■ Telephone 858.558.6900 ■ Fax 858.558.6159 services and, therefore, has no opinion regarding the accuracy of the as-graded elevations or surface geometry with respect to the approved grading plans or proper surface drainage. GRADING Fine grading of the sheet-graded pad consisted of removing compacted fill and granitic rock to achieve finish grade elevations. Due to cut/fill transitions, the cut portions of the pads (and shallow fill areas) were overexcavated at least 5 feet below finish grade. The lateral limits of the overexcavation extended at least 5 feet outside the building footprints. Prior to placing fill, the ground surface was scarified, if practical, moisture conditioned, and compacted prior to receiving fill. Grading consisted of maximum cuts and fills of approximately 9 feet, respectively. The grading was performed in conjunction with testing and observation services provided by Geocon Incorporated. Fill soils derived from on-site and imported excavations were placed and compacted in layers until the design elevations were attained. Fill Materials and Placement Procedures The on-site fill materials generally consisted of silty sands with gravel, cobble, and boulder sized rock fragments. The oversize rock hold-down restrictions presented in our referenced report were modified by Ryan Companies as discussed in Section I. 0 Conclusions and Recommendations. The fills were placed in lifts no thicker than would allow for adequate bonding and compaction. The soil was moisture conditioned as necessary and mixed during placement. Field In-Place Density and Laboratory Testing During the grading operation, compaction procedures were observed and in-place density tests were performed to evaluate the relative compaction of the fill material. The in-place density tests were performed in general conformance with ASTM Test Method D 6938 (nuclear). Results of the field density tests and moisture content tests performed during grading have been summarized on Table I. In general, the in-place density test results indicate that the fill, at the locations tested, has a relative compaction of at least 90 percent. Laboratory tests were performed on samples of materials used for fill to evaluate moisture-density relationships, optimum moisture content and maximum dry density (ASTM D 1557). Additionally, laboratory tests were performed on samples to determine the expansion potential (ASTM D 4829) and the water-soluble sulfate content (California Test Method No. 417). The results of the laboratory tests are summarized on Tables II through V. Project No. 06442-32-28A - 2 -March 8, 2018 Finish Grade Soil Conditions Observations and laboratory test results indicate that the prevailing soils within 3 feet of finish grade of the building pads have Expansion Index (El's) of zero and are considered to be "non-expansive" (expansion index [EI] of 20 or less) as defined by 2016 California Building Code (CBC) Section 1803.5.3 (see Table 1). Table V presents a summary of the expansion classification for the prevailing finish grade soils on each lot. TABLE 1 EXPANSION CLASSIFICATION BASED ON EXPANSION INDEX Expansion Index (EI) Expansion Classification 2016 CBC Expansion Classification 0-20 Very Low Non-Expansive 21-50 Low 51-90 Medium 91 -130 High Expansive Greater Than 130 Very High We performed laboratory tests on samples of the site materials to evaluate the percentage of water- soluble sulfate. Results from the laboratory water-soluble sulfate content testing are presented in Table IV and indicate that the on-site materials at the locations tested possess a "Not Applicable" and "SO" sulfate exposure to concrete structures as defined by 2016 CBC Section 1904 and ACI 318-14 Chapter 19. The CBC provides no specific recommendations for concrete subjected to "not applicable" sulfate exposure. It should be noted that the presence of water-soluble sulfates is not a visually discernible characteristic; therefore, other soil samples from the site could yield different concentrations. Additionally, over time landscaping activities (i.e. addition of fertilizers and other soil nutrients) may affect the concentration. Geocon Incorporated does not practice m the field of corrosion engmeermg. Therefore, it is recommended that further evaluation by a corrosion engineer be performed if improvements are planned that are susceptible to corrosion. SOIL AND GEOLOGIC CONDITIONS The soil and geologic conditions encountered during grading were found to be generally similar to those described in the referenced geotechnical report. Project No. 06442-32-28A - 3 -March 8, 2018 CONCLUSIONS AND RECOMMENDATIONS 1.0 General 1.1 Based on observations and test results, it is the opinion of Geocon Incorporated that the grading within the structure footprints on the subject building pads has been performed in substantial conformance with the recommendations of the referenced project soil report. Soil and geologic conditions encountered during grading which differ from those anticipated by the project soil report are not uncommon. Where such conditions required a significant modification to the recommendations of the project soil reports, they have been described herein. 1.2 During grading, Ryan Companies revised the rock size placement criteria to: • Rock fragments greater than 6 inches in maximum dimension should not be placed within one foot of finish grade; • Rock Fragments greater than 14 inches in maximum dimension should not be placed within ten feet of finish grade. 1.3 Based on our observations during grading, the original rock hold-down restrictions were not strictly followed. Ryan Company representatives were made aware of the grading contractor's inability to adhere to these restrictions and Geocon was informed that any future impacts to subcontractors resulting from the oversize materials would be managed by the Ryan Companies. The presence of over-size rock in the upper portions of the embankments however should not adversely affect the performance of the compacted fill. 2.0 Future Grading and Improvements 2.1 Additional grading or planned improvements performed at the site should be accomplished in conjunction with our geotechnical services. Plans for any future improvements should be reviewed by Geocon Incorporated prior to finalizing. Any additional trench backfill in excess of I-foot-thick should be compacted to at least 90 percent relative compaction. This office should be notified at least 48 hours prior to commencing additional grading or backfill operations. 3.0 Seismic Design Criteria 3.1 We used the computer program US Seismic Design Maps, provided by the USGS . Table 3 summarizes site-specific design criteria obtained from the 2016 California Building Code (CBC; Based on the 2015 International Building Code [IBC] and ASCE 7-10), Chapter 16 Structural Design, Section 1613 Earthquake Loads. The short spectral response uses a period of 0.2 seconds. The values presented in Table 3 are for the risk-targeted maximum considered Project No. 06442-32-28A - 4 -March 8, 2018 earthquake (MCER)-Based on soil conditions and planned grading, Buildings B and C may be designed using Site Class D. We evaluated the Site Class based on the discussion in Section 1613.3.2 of the 2016 CBC and Table 20.3-1 of ASCE 7-10. TABLE 3 2016 CBC SEISMIC DESIGN PARAMETERS Parameter Value 2016 CBC Reference Site Class D Section 1613.3.2 Spectral Response -Class B (0.2 sec), Ss 1.039 g Figure 1613.3.1 (1) Spectral Response -Class B (1 sec), S1 0.404 g Figure 1613.3.1(2) Site Coefficient, Fa 1.084 Table 1613.3.3(1) Site Coefficient, Fv 1.596 Table 1613.3.3(2) Maximum Considered Earthquake 1.127 g Section 1613.3.3 (Eqn 16-37) Spectral Response Acceleration (0.2 sec), SMs Maximum Considered Earthquake 0.644 g Section 1613.3.3 (Eqn 16-38) Spectral Response Acceleration (1 sec), SM1 5% Damped Design 0.751 g Section 1613.3.4 (Eqn 16-39) Spectral Response Acceleration (0.2 sec), Sos 5% Damped Design 0.430 g Section 1613.3.4 (Eqn 16-40) Spectral Response Acceleration (1 sec), Soi 3.2 Conformance to the criteria for se1srmc design does not constitute any guarantee or assurance that significant structural damage or ground failure will not occur in the event of a maximum level earthquake. The primary goal of seismic design is to protect life and not to avoid all damage, since such design may be economically prohibitive. 4.0 Foundation and Concrete Slab-On-Grade Recommendations 4.1 The project is suitable for the use of continuous strip footings, isolated spread footings, or appropriate combinations thereof, provided the preceding grading recommendations are followed. 4.2 The following recommendations are for the planned structures and assume that the foundation systems for the structures will bear on properly compacted fill. Building A: continuous footings should be at least 12 inches wide and should extend at least 24 inches below lowest adjacent pad grade. Isolated spread footings should be at least two feet square and extend a minimum of 24 inches below lowest adjacent pad grade. Project No. 06442-32-28A - 5 -March 8, 2018 4.3 Isolated footings, which are located beyond the perimeter of the buildings and support structural elements connected to the building, should be connected to the building foundation system with grade beams. 4.4 The project structural engmeer should design the reinforcement for the footings. For continuous footings, however, we recommend minimum reinforcement consisting of four No. 5 steel reinforcing bars, two placed near the top of the footing and two placed near the bottom. The project structural engineer should design reinforcement of isolated spread footings. 4.5 The recommended allowable bearing capacity for foundations designed as recommended above is 2,500 pounds per square foot (psf) for foundations in properly compacted fill soil. This soil bearing pressure may be increased by 300 psf and 500 psf for each additional foot of foundation width and depth, respectively, up to a maximum allowable soil bearing of 4,000 psf. 4.6 The allowable bearing pressures recommended above are for dead plus live loads only and may be increased by up to one-third when considering transient loads such as those due to wind or seismic forces. 4.7 The estimated maximum total and differential settlement for the planned structures due to foundation loads is 1 inch and ¾ inch, respectively over a span of 40 feet. 4.8 Building interior concrete slabs-on-grade should be at least five inches in thickness. Slab reinforcement should consist of No. 3 steel reinforcing bars spaced 18 inches on center in both directions placed at the middle of the slab. If the slabs will be subjected to heavy loads, consideration should be given to increasing the slab thickness and reinforcement. The project structural engineer should design interior concrete slabs-on-grade that will be subjected to heavy loading (i.e., fork lift, heavy storage areas). Subgrade soils supporting heavy loaded slabs should be compacted to at least 95 percent relative compaction. 4.9 A vapor retarder should underlie slabs that may receive moisture-sensitive floor coverings or may be used to store moisture-sensitive materials. The vapor retarder design should be consistent with the guidelines presented in the American Concrete Institute's (ACI) Guide for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials (ACI 302.2R-06). In addition, the membrane should be installed in a manner that prevents puncture in accordance with manufacturer's recommendations and ASTM requirements. The project architect or developer should specify the type of vapor retarder used based on the type of floor covering that will be installed and if the structure will possess a humidity-controlled environment. Project No. 06442-32-28A - 6 -March 8, 2018 4.10 The project foundation engineer, architect, and/or developer should determine the thickness of bedding sand below the slab. Typically, 3 to 4 inches of sand bedding is used in the San Diego County area. Geocon should be contacted to provide recommendations if the bedding sand is thicker than 6 inches. 4.11 Exterior slabs not subject to vehicle loads should be at least 4 inches thick and reinforced with 6x6-W2.9/W2.9 (6x6-6/6) welded wire mesh or No. 3 reinforcing bars spaced at 24 inches on center in both directions to reduce the potential for cracking. The mesh should be placed in the middle of the slab. Proper mesh positioning is critical to future performance of the slabs. The contractor should take extra measures to provide proper mesh placement. Prior to construction of slabs, the subgrade should be moisture conditioned to at least optimum moisture content and compacted to a dry density of at least 90 percent of the laboratory maximum dry density in accordance with ASTM 1557. 4.12 To control the location and spread of concrete shrinkage and/or expansion cracks, it is recommended that crack-control joints be included in the design of concrete slabs. Crack- control joint spacing should not exceed, in feet, twice the recommended slab thickness in inches (e.g., 10 feet by 10 feet for a 5-inch-thick slab). Crack-control joints should be created while the concrete is still fresh using a grooving tool or shortly thereafter using saw cuts. The structural engineer should take criteria of the American Concrete Institute into consideration when establishing crack-control spacing patterns. 4 .13 The above foundation and slab-on-grade dimensions and rmrumum reinforcement recommendations are based upon soil conditions only, and are not intended to be used in lieu of those required for structural purposes. The project structural engineer should design actual concrete reinforcement. 4.14 No special subgrade presaturation is deemed necessary prior to placement of concrete. However, the slab and foundation subgrade should be moisture conditioned as necessary to maintain a moist condition as would be expected in any concrete placement. 4 .15 The recommendations of this report are intended to reduce the potential for cracking of slabs due to expansive soil (if present), differential settlement of existing soil or soil with varying thicknesses. However, even with the incorporation of the recommendations presented herein, foundations, stucco walls, and slabs-on-grade placed on such conditions may still exhibit some cracking due to soil movement and/or shrinkage. The occurrence of concrete shrinkage cracks is independent of the supporting soil characteristics. Their occurrence may be reduced and/or controlled by limiting the slump of the concrete, proper concrete Project No. 06442-32-28A -7 -March 8, 2018 placement and curing, and by the placement of crack control joints at periodic intervals, in particular, where re-entrant slab corners occur. 4.16 A representative of Geocon Incorporated should observe the foundation excavations prior to the placement of reinforcing steel or concrete to check that the exposed soil conditions are consistent with those anticipated. If unanticipated soil conditions are encountered, foundation modifications may be required. 4.17 Geocon Incorporated should be consulted to provide additional design parameters as required by the structural engineer. 5.0 Lateral Loading 5.1 To resist lateral loads, a passive earth pressure equivalent to a fluid with a density of 300 pounds per cubic foot (pcf) should be used for design of footings or shear keys poured neat against properly compacted granular fill soils or undisturbed formational material. The passive pressure assumes that a horizontal ground surface extends away from the base of the wall at least five feet or three times the depth of the surface generating the passive pressure, whichever is greater. The upper 12 inches of material in areas not protected by floor slabs or pavement should not be included in design for passive resistance. 5 .2 If friction is to be used to resist lateral loads, an allowable coefficient of friction between soil and concrete of 0.35 should be used for design for footings founded in compacted fill. The recommended passive pressure may be used concurrently with frictional resistance without reduction and may be increased by one-third for transient wind or seismic loading. 6.0 Retaining Walls 6.1 Retaining walls not restrained at the top and having a level backfill surface should be designed for an active soil pressure equivalent to the pressure exerted by a fluid with a density of 35 pounds per cubic foot (pcf). Where the backfill will be inclined at 2: 1 (horizontal:vertical), an active soil pressure of 50 pcf is recommended. These soil pressures assume that the backfill materials within an area bounded by the wall and a 1: 1 plane extending upward from the base of the wall possess an Expansion Index less than 50. Imported low expansion granular soil would be required. 6.2 If moderately expansive soils (EI greater than 50) are used for backfill, the active earth pressure would increase to 80 pcf for level backfill and 95 pcf for backfill inclined at 2: 1 (horizontal:vertical). These soil pressures assume that the backfill materials within an area bounded by the wall and a 1: 1 plane extending upward from the base of the wall possess an Project No. 06442-32-28A -8 -March 8, 2018 Expansion Index less than 130. Backfill material exhibiting an Expansion Index greater than 130 should not be used. 6.3 Retaining walls shall be designed to ensure stability against overturning sliding, excessive foundation pressure and water uplift. Where a keyway is extended below the wall base with the intent to engage passive pressure and enhance sliding stability, it is not necessary to consider active pressure on the keyway. 6.4 Where walls are restrained from movement at the top, an additional uniform pressure of 8H psf (where H equals the height of the retaining wall portion of the wall in feet) should be added to the active soil pressure where the wall possesses a height of 8 feet or less and 12H where the wall is greater than 8 feet. For retaining walls subject to vehicular loads within a horizontal distance equal to two-thirds the wall height, a surcharge equivalent to two feet of fill soil should be added (total unit weight of soil should be taken as 130 pcf). 6.5 Soil contemplated for use as retaining wall backfill, including import materials, should be identified in the field prior to backfill. At that time Geocon Incorporated should obtain samples for laboratory testing to evaluate its suitability. Modified lateral earth pressures may be necessary if the backfill soil does not meet the required expansion index or shear strength. City or regional standard wall designs, if used, are based on a specific active lateral earth pressure and/or soil friction angle. In this regard, on-site soil to be used as backfill may or may not meet the values for standard wall designs. Geocon Incorporated should be consulted to assess the suitability of the on-site soil for use as wall backfill if standard wall designs will be used. 6.6 Unrestrained walls will move laterally when backfilled and loading is applied. The amount of lateral deflection is dependent on the wall height, the type of soil used for backfill, and loads acting on the wall. The wall designer should provide appropriate lateral deflection quantities for planned retaining walls structures, if applicable. These lateral values should be considered when planning types of improvements above retaining wall structures. 6. 7 Retaining walls should be provided with a drainage system adequate to prevent the buildup of hydrostatic forces and should be waterproofed as required by the project architect. The use of drainage openings through the base of the wall (weep holes) is not recommended where the seepage could be a nuisance or otherwise adversely affect the property adjacent to the base of the wall. If conditions different than those described are expected, or if specific drainage details are desired, Geocon Incorporated should be contacted for additional recommendations. Project No. 06442-32-28A -9 -March 8, 2018 6.8 In general, wall foundations having a minimum depth of 24 inches and width of 12 inches may be designed for an allowable soil bearing pressure of 2,000 psf. The recommended allowable soil bearing pressure may be increased by 300 psf and 500 psf for each additional foot of foundation width and depth, respectively, up to a maximum allowable soil bearing pressure of 4,000 psf. 6.9 The proximity of the foundation to the top of a slope steeper than 3: 1 could impact the allowable soil bearing pressure. Therefore, Geocon Incorporated should be consulted where such a condition is anticipated. As a minimum, wall footings should be deepened such that the bottom outside edge of the footing is at least seven feet from the face of slope when located adjacent and/or at the top of descending slopes. 6.10 The structural engineer should determine the Seismic Design Category for the project in accordance with Section 1613.3.5 of the 2016 CBC or Section 11.6 of ASCE 7-10. For structures assigned to Seismic Design Category of D, E, or F, retaining walls that support more than 6 feet of backfill should be designed with seismic lateral pressure in accordance with Section 1803.5.12 of the 2016 CBC. The seismic load is dependent on the retained height where H is the height of the wall, in feet, and the calculated loads result in pounds per square foot (psf) exerted at the base of the wall and zero at the top of the wall. A seismic load of 21H should be used for design. We used the peak ground acceleration adjusted for Site Class effects, PGAM, of 0.438g calculated from ASCE 7-10 Section 11.8.3 and applied a pseudo-static coefficient of 0.33. 6.11 If conditions different than those described are anticipated, or if specific drainage details are desired, Geocon Incorporated should be contacted for additional recommendations. If on- site highly expansive soils are used as retaining wall backfill, modifications to the design parameters provided above would be required. 7.0 Mechanically Stabilized Earth (MSE) Retaining Walls 7 .1 We are providing geotechnical parameters for mechanically stabilized earth (MSE) reinforced retaining walls that are being considered for the project. Geogrid retaining walls are alternative walls that consist of modular block facing units with geogrid reinforced earth behind the block. The geogrid attaches to the block units and is typically placed at specified vertical intervals and embedment lengths. Spacing and lengths are based on the wall height and type of soil used for backfill. 7.2 For design of MSE retaining walls, we recommend an active soil pressure equivalent to the pressure exerted by a fluid density of 35 pound per cubic foot (pct) for level backfill. Where Project No. 06442-32-28A -IO -March 8, 2018 the backfill will be inclined at 2: 1 (horizontal:vertical), an active soil pressure of 50 pcf is recommended. Expansive soil should not be used as backfill material behind retaining walls. Soil placed for retaining wall backfill should have an Expansion Index ~ 50 and should meet the geotechnical parameters listed in Table 7. TABLE 7 GEOTECHNICAL PARAMETERS FOR GEOSYNTHETIC REINFORCED WALLS Parameter Reinforced Zone Retained Zone Foundation Zone Angle of Internal Friction 30 degrees 30 degrees 30 degrees Cohesion 0 psf 0 psf 0 psf Wet Unit Weight 130 pcf 130 pcf 130 pcf Notes: Reinforced Zone is the area where geotextile reinforcing grid is placed. Retained Zone is the area behind the reinforced zone and within a 1: 1 plane extending up and out from the bottom of the reinforced zone to a horizontal distance equal to the height of the retaining wall. Foundation Zone is the area below the reinforced zone and within a 1: 1 plane extending down and out from the bottom of the wall block. 7.3 Based on previous laboratory testing, the on-site soils should meet the soil properties listed in Table 7 and soil properties specified by the wall engineer. Laboratory testing should be performed on samples of the proposed soils to check if the shear strength of the soil meets the design values and additional soil specifications required by the wall engineer. Results, if they vary significantly from those in Table 7, should be provided to the wall designer for his review and determination if modifications to the design are warranted. The designer should re-evaluate stability of the walls based on the shear strength test results. 7.4 An allowable soil bearing pressure of 2,500 pounds per square foot (psf) can be used for foundation design and calculations for wall bearing. This bearing pressure assumes a minimum foundation width and depth of 12 inches. The allowable soil bearing pressure may be increased by 300 psf and 500 psf for each additional foot of foundation width and depth, respectively, up to a maximum allowable soil-bearing pressure of 4,000 psf. The foundation bearing zone of the wall can be considered across the reinforced zone of the wall. 7 .5 The bearing pressure may be increased by one-third for transient loads due to wind or seismic forces. 7 .6 The proximity of the foundation to the top of a slope steeper than 3: 1 could impact the allowable soil bearing pressure. As a minimum, wall footings should be deepened such that the bottom outside edge of the footing is at least seven feet from the face of slope when located adjacent and/or at the top of descending slopes. Project No. 06442-32-28A -11 -March 8, 2018 7.7 Soil placed within the reinforced zone of the wall should be compacted to at least 90 percent of the laboratory maximum dry density at or slightly above optimum moisture content. This is applicable to the entire embedment width of the geogrid reinforcement. Typically, wall designers specify no heavy compaction equipment within three feet of the face of the wall to reduce the potential for wall deformation during construction. However, smaller equipment (e.g., walk-behind, self-driven compactors or hand whackers) can be used to compact the materials without causing deformation of the wall. If the designer specifies no compaction effort for this zone, then the uncompacted soil does not meet the minimum shear strength (angle of internal friction) presented in Table 7 and this portion of geogrid should not be relied upon for reinforcement, and overall embedment lengths will have to be increased to account for the difference. 7.8 The wall should be provided with a drainage system sufficient enough to prevent excessive seepage through the wall and water at the base of the wall to prevent hydrostatic pressures behind the wall. 7.9 Geosynthetic reinforcement must elongate to develop full tensile resistance. This elongation generally results in movement at the top of the wall. The amount of movement is dependent upon the height of the wall (e.g., higher walls rotate more) and the type of geogrid reinforcing used. In addition, over time geogrid has been known to exhibit creep (sometimes as much as 5 percent) and can undergo additional movement. Given this condition, structures and pavement placed within the reinforced and retained zones of the wall might undergo movement. Planned buildings and settlement sensitive improvements should not be placed within the reinforced and retained zones of the wall. 8.0 Slope Maintenance 8.1 Slopes that are steeper than 3: 1 (horizontal:vertical) may, under conditions which are both difficult to prevent and predict, be susceptible to near surface slope instability. The instability is typically limited to the outer three feet of a portion of the slope and does not directly impact the improvements on the pad areas above or below the slope. The occurrence of surficial instability is more prevalent on fill slopes and is usually preceded by a period of heavy rainfall, excessive irrigation, or the migration of subsurface seepage. The disturbance and/or loosening of the surficial soils, as might result from root growth, soil expansion, or excavation for irrigation lines and slope planting, may also be a significant contributing factor for surficial instability. It is, therefore, recommended that, to the maximum extent practical (a) disturbed/loosened surficial soils be either removed or properly recompacted, (b) irrigation systems be periodically inspected and maintained to eliminate leaks and excessive irrigation, and (c) surface drains on, and adjacent to, slopes should be periodically maintained to preclude ponding or erosion. It should be noted that Project No. 06442-32-28A -12 -March 8, 20 I 8 although the incorporation of the above recommendations should reduce the potential for surficial slope instability, it will not eliminate the possibility, and, therefore, it may be necessary to rebuild or repair a portion of the project's slopes in the future. 9.0 Site Drainage and Moisture Protection 9 .1 Adequate site drainage is critical to reduce the potential for differential soil movement, erosion and subsurface seepage. Under no circumstances should water be allowed to pond adjacent to footings. The site should be graded and maintained such that surface drainage is directed away from structures in accordance with 2016 CBC 1804.4 or other applicable standards. In addition, surface drainage should be directed away from the top of slopes into swales or other controlled drainage devices. Roof and pavement drainage should be directed into conduits that carry runoff away from the proposed structure. 9.2 Underground utilities should be leak free. Utility and irrigation lines should be checked periodically for leaks, and detected leaks should be repaired promptly. Detrimental soil movement could occur if water is allowed to infiltrate the soil for prolonged periods of time. LIMITATIONS The conclusions and recommendations contained herein apply only to our work with respect to grading and represent conditions at the date of our final observation on February 23, 2018. Changes in the conditions of a property can occur with the passage of time due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, resulting from legislation or the broadening of knowledge in the fields of geotechnical engineering or geology. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. Any subsequent grading should be done in conjunction with our observation and testing services. As used herein, the term "observation" implies only that we observed the progress of the work with which we agreed to be involved. Our services did not include the evaluation or identification of the potential presence of hazardous or corrosive materials. Our conclusions and opinions as to whether the work essentially complies with the job specifications are based on our observations, experience and test results. Due to the inaccuracies inherent in most field and laboratory soil tests, and the necessary assumption that the relatively small soil sample tested is representative of a significantly larger volume of soil, future tests of the same soil, location or condition should not be expected to duplicate specific individual test results of this report. Subsurface conditions, and the accuracy of tests used to measure such conditions, can vary greatly at any time. We make no warranty, express or implied, except that Project No. 06442-32-28A -13 -March 8, 2018 ~GE OCON TABLE 1 SUMMARY OF FIELD DENSITY TEST RESULTS Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-32-28A Date Elev. >¾" Max. Opt. Field Field Relative Required Test No. or Curve Dry Moist Dry Moisture Relative (MM/DD Location Depth No. Rock Density Content Density Content Compaction Compaction /YY) (%) (%) Pre. No. Re. (feet) (pct) (%) (pct) (%) (%) l 11/28/17 E Building C 378 12 0 132.S 9.8 116.4 3.3 88 90 I A 11/29/17 E Building C 378 12 0 132.S 9.8 118. l 5.2 89 90 I B 11/30/17 E Building C 378 12 0 132.S 9.8 122.1 11.0 92 90 2 11/29/17 E Driveway E 382 12 0 132.S 9.8 118.S 5.3 89 90 2 A 11/30/17 E Driveway E 382 12 0 132.S 9.8 122.8 10.9 93 90 3 12/01 /17 E Building C 379 4 0 134.9 7.4 124.S 8.7 92 90 4 12/01/17 E Building C 378 4 0 134.9 7.4 119.8 4.0 89 90 4 R 12,1()4/1'.7 E BuileiAg 8 J-1-8 4 0 +¼-,9. -1-4 +w-k ~ 8-9-90 s 12/04/17 E BuildingC 381 4 0 134.9 7.4 125.0 8.8 93 90 6 12/04/17 E building C 380 4 0 134.9 7.4 126.1 9.1 93 90 7 12/04/17 E Building C 379 4 0 134.9 7.4 125.6 8.9 93 90 8 12/04/17 E Building C 380 4 0 134.9 7.4 124.6 8.5 92 90 9 12/05/17 E Building C 381 4 0 134.9 7.4 126.1 8.5 93 90 10 12/05/17 E Building C 380 4 0 134.9 7.4 123.S 9.3 92 90 11 12/07/17 E Building C 383 4 0 134.9 7.4 128.4 8.6 95 90 12 12/07/17 E Building C 382 4 0 134.9 7.4 127.0 8.9 94 90 13 12/07/17 E Building C 382 4 0 134.9 7.4 127.1 8.8 94 90 14 12/08/17 w Building C 386 4 0 134.9 7.4 118.4 4.4 88 90 14 A 12/11/17 w Building C 386 4 0 134.9 7.4 123.6 9.1 92 90 IS 12/08/17 w Building C 385 4 0 134.9 7.4 120.S 5.1 89 90 IS A 12/11/17 w Building C 385 4 0 134.9 7.4 122.4 9.4 91 90 16 12/11 /l 7 w Building C 388 4 0 134.9 7.4 124.7 9.2 92 90 17 12/11 /17 w Building C 386 4 0 134.9 7.4 126.6 8.5 94 90 18 12/12/17 w Building C 386 4 0 134.9 7.4 123 .7 9.3 92 90 19 12/12/17 w Building C 386 4 0 134.9 7.4 122.3 8.5 91 90 20 12/12/17 E BuildingC 384 4 0 134.9 7.4 124.4 8.8 92 90 21 12/13/17 w BuildingC 387 4 0 134.9 7.4 122.2 8.6 91 90 22 12/13/17 w Building C 385 4 0 134.9 7.4 125.1 10.4 93 90 23 12/13/17 E Building C 384 4 0 134.9 7.4 126.4 8.4 94 90 24 12/13/17 E Building C 383 4 0 134.9 7.4 123 .7 9.1 92 90 ~GE OCON TABLE 1 SUMMARY OF FIELD DENSITY TEST RES UL TS Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-32-28A Elev. >¾" Max. Opt. Field Field Relative Required Test No. Date Curve Dry Moist Dry Moisture Relative (MM/DD Location or Rock Compaction /YY) Depth No. co;.,) Density Content Density Content (%) Compaction Pre. No . Re. (feet) (pct) (%) (pct) (%) (%) ~ R l2,114ff7 E 9Fi¥e't1,•ay ~ J.-14 4 0 +J4.,.9. M -U&J ~ && 90 26 12/15/17 SE Building C 375 4 0 134.9 7.4 124.1 8.1 92 90 27 12/15/17 SE Building C 376 4 0 134.9 7.4 118.4 5.5 88 90 27 A 12/15/17 SE Building C 376 4 0 134.9 7.4 122.9 7.8 91 90 28 12/15/17 SE Building C 377 4 u 134.9 7.4 120.0 6.1 89 90 28 A 12/15/17 SE Building C 377 4 0 134.9 7.4 124.5 8.3 92 90 29 12/15/17 s Building C 378 4 0 134.9 7.4 121.9 8.0 90 90 30 12/15/17 s Building C 380 4 0 134.9 7.4 125.2 8.7 93 90 31 12/18/17 E Driveway F 377 4 0 134.9 7.4 120.6 4.3 89 90 3 I A 12/18/17 E Driveway F 377 4 0 134.9 7.4 124.4 8.9 92 90 32 12/18/17 SE Building C 383 4 0 134.9 7.4 125.9 8.2 93 90 33 12/18/17 w Building C 388 4 0 134.9 7.4 125.8 9.0 93 90 34 12/18/17 E Driveway F 378 4 0 134.9 7.4 122.7 9.6 91 90 35 12/19/17 w Building C 389 4 0 134.9 7.4 125.9 8.9 93 90 36 12/19/17 Mid Building C 387 4 0 134.9 7.4 124.7 8.5 92 90 37 12/19/17 E Building C 385 4 0 134.9 7.4 124.3 8.8 92 90 38 12/20/17 E Building C 385 4 0 134.9 7.4 120.6 4.3 89 90 38 A 12/21/17 E Building C 385 4 0 134.9 7.4 122.7 8.9 91 90 39 12/20/17 E Building C 384 4 0 134.9 7.4 120.3 4.1 89 90 39 A 12/21/17 E Building C 384 4 0 134.9 7.4 123.1 9.1 91 90 40 12/20/17 E Driveway F 380 4 0 134.9 7.4 119.8 4.4 89 90 40 A 12/2 1/17 E Driveway F 380 4 0 134.9 7.4 122.2 9.3 91 90 41 12/22/17 Driveway F 381 4 0 134.9 7.4 124.3 8.1 92 90 42 12/22/17 Mid Building C 387 4 0 134.9 7.4 124.0 7.9 92 90 43 12/22/17 w Building C 389 4 0 134.9 7.4 125.6 7.6 93 90 44 12/26/1 7 SE Building C 384 4 0 134.9 7.4 120.6 2.5 89 90 44 A 12/27/1 7 SE Building C 384 4 0 134.9 7.4 120.1 3.4 89 90 44 B 12/27/17 SE Building C 384 4 0 134.9 7.4 124.7 8.9 92 90 45 12/26/17 w Building B 386 4 0 134.9 7.4 118.1 2.4 88 90 45 A 01 /04/18 w BuildingB 386 4 0 134.9 7.4 120.5 2.9 89 90 ~G E OCON TABLE 1 SUMMARY OF FIELD DENSITY TEST RES UL TS Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-32-28A Elev. >¾" Max. Opt. Field Field Relative Required Test No. Date Curve Moist Dry Moisture Relative (MM/DD Location or Rock Dry Compaction /YY) Depth No. (%) Density Content Density Content (%) Compaction Pre. No. Re. (feet) (pct) (%) (pct) (%) (%) 45 B 01/05/18 w Building B 386 4 0 134.9 7.4 125.8 8.9 93 90 46 12/26/17 SE Building C 380 4 0 134.9 7.4 120.3 4.5 89 90 46 A 12/26/17 SE Building C 380 4 0 134.9 7.4 123.1 8.5 91 90 47 12/1 6/17 w Building C 384 4 0 134.9 7.4 125.1 8.6 93 90 48 12/26/17 w Building C 383 4 0 134.9 7.4 125.5 8.7 93 90 49 12/26/17 E Driveway F 368 4 0 134.9 7.4 121.3 8.5 90 90 50 12/28/17 SE Building C 381 4 0 134.9 7.4 122.9 8.8 91 90 51 12/28/17 s Building C 385 4 0 134.9 7.4 125.3 8.7 93 90 52 12/28/17 NW Building C 385 4 0 134.9 7.4 127.4 9.0 94 90 53 12/29/17 s Building C 386 4 0 134.9 7.4 125.6 8.6 93 90 54 12/29/17 NW Building C 386 4 0 134.9 7.4 119.6 2.6 89 90 54 A 12/29/17 NW Building C 386 4 0 134.9 7.4 121.9 8.5 90 90 55 12/29/17 SW Building C 390 4 0 134.9 7.4 123.8 9.1 92 90 56 12/29/17 NE Building C 385 4 0 134.9 7.4 125.4 8.9 93 90 57 12/29/17 SE Building B 385 4 0 134.9 7.4 119.8 3.8 89 90 57 A 01/02/18 SE Building B 385 4 0 134.9 7.4 120.6 2.9 89 90 57 B 01/02/18 SE BuildingB 385 4 0 134.9 7.4 120.3 4.6 89 90 57 C 01/03/18 SE Building B 385 4 0 134.9 7.4 120.3 3.8 89 90 57 D 01/03/18 SE Building B 385 4 0 134.9 7.4 118.4 3.0 88 90 57 E 01 /04/18 SE Building B 385 4 () 134.9 7.4 124.2 8.5 92 90 58 12/2 9/17 SW Building B 383 4 0 134.9 7.4 116.7 2.0 87 90 58 A 01/02/18 SW Building B 383 4 0 134.9 7.4 119.2 2.2 88 90 58 B 01 /02/18 SW Building B 383 4 0 134.9 7.4 119.1 4.2 88 90 58 C 01 /03/18 SW Building B 383 4 0 134.9 7.4 119.7 4.3 89 90 58 D 01 /03/18 SW Building B 383 4 0 134.9 7.4 120.6 2.5 89 90 58 E 01 /04/18 SW Building B 383 4 0 134.9 7.4 124.0 8.9 92 90 59 01/02/18 w Building B 386 16 20 136.4 6.6 120.7 3.2 88 90 59 A 01 /04/18 w Building B 386 16 20 136.4 6.6 126.4 8.0 93 90 60 01/02/18 E Building B 386 4 0 134.9 7.4 119.4 4.1 89 90 60 A 01/04/18 E Building B 386 4 . 0 134.9 7.4 122.6 9.1 91 90 ~ G E OCON TABLE 1 SUMMARY OF FIELD DENSITY TEST RESULTS Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-32-28A Date Elev. >¾" Max. Opt. Field Field Relative Required Test No. or Curve Dry Moist Dry Moisture Relative (MM/DD Location Depth No. Rock Density Content Density Content Compaction Compaction /YY) (%) (%) Pre. No. Re. (feet) (pct) (%) (pct) (%) (%) 61 01/03/18 w Driveway F 387 4 0 134.9 7.4 119.6 3.5 89 90 61 A 01/05/18 w Driveway F 387 4 0 134.9 7.4 123.7 9.1 92 90 62 01/03/18 E Driveway F 381 4 0 134.9 7.4 120.4 3.9 89 90 62 A 01/05/18 E Driveway F 381 4 0 134.9 7.4 122.2 8.5 91 90 63 01/04/18 NW Building B 387 4 0 134.9 7.4 120.1 2.6 89 90 63 A 01 /05/18 NW Building B 387 4 0 134.9 7.4 124.5 9.0 92 90 FG 64 01 /08/18 E Building C 386 4 0 134.9 7.4 124.8 8.8 93 90 FG 65 01 /08/18 E Building C 387 4 0 134.9 7.4 125.4 9.2 93 90 FG 66 01 /08/18 N Building C 388 4 () 134.9 7.4 126.1 9.0 93 90 FG 67 01/08/18 w Building C 389 4 0 134.9 7.4 122.7 8.8 91 90 FG 68 01 /08/18 w Building C 391 4 0 134.9 7.4 123 .9 9.3 92 90 69 01/16/18 w Driveway F 386 4 0 134.9 7.4 124.3 8.5 92 90 70 01/16/18 E Driveway F 383 4 0 134.9 7.4 125.1 8.8 93 90 71 01/16/18 N Building A 392 16 20 136.4 6.6 120.3 4.2 88 90 71 A 01/20/18 N Building A 392 16 20 136.4 6.6 126.0 8.2 92 90 72 01/16/18 s Building A 392 16 20 136.4 6.6 121.0 4.5 89 90 72 A 01/20/18 s Building A 392 16 20 136.4 6.6 126.5 7.8 93 90 1:J. -R Ql,l)(j,/j8 9ri¥eway P ~ -1-6 -l-0 +J¼ +4 -l--1-8-d ~ &9-90 74 01/18/18 w BuildingB 388 4 0 134.9 7.4 122.8 9.0 91 90 FG 75 01/18/18 w Building B 390 4 0 134.9 7.4 126.3 8.8 94 90 FG 76 01 /18/18 w Building B 389 4 0 134.9 7.4 125.8 9.2 93 90 fG 77 01/18/18 E Building B 388 4 0 134.9 7.4 126.7 8.6 94 90 FG 78 01/18/18 E Building B 387 4 0 134.9 7.4 124.4 9.1 92 . 90 79 01/19/18 w Building A 391 16 10 133.5 7.4 122.5 8.8 92 90 80 01/19/18 E Building A 393 16 10 133.5 7.4 126.1 8.6 94 90 81 01/19/18 Building A 394 16 10 133.5 7.4 123.7 9.0 93 90 82 01/20/18 E Edge of Site 375 4 0 134.9 7.4 126.1 9.1 93 90 83 01/20/18 s Building A 388 16 10 133.5 7.4 125.3 8.6 94 90 84 01/23/18 E Building A 390 16 10 133.5 7.4 122.9 8.8 92 90 85 01/23/18 w Building A 394 16 10 133.5 7.4 123.7 9.2 93 90 ~GE OCON TABLE 1 SUMMARY OF FIELD DENSITY TEST RESULTS Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-32-28A Date Elev. >¾" Max. Opt. Field Field Relative Required Test No. or Curve Dry Moist Dry Moisture Relative (MM/DD Location Rock Compaction /YY) Depth No. (%) Density Content Density Content (%) Compaction Pre. No. Re. (feet) (pcf) (%) (pct) (%) (%) 86 01/24/18 E Building A 393 16 0 130.7 8.2 122.5 9.4 94 90 87 01 /25/18 w Building A 395 16 10 133.5 7.4 124.6 8.6 93 90 88 01/25/18 E Building A 390 16 0 130.7 8.2 121.5 9.3 93 90 89 01/30/18 SE Building A 389 4 0 134.9 7.4 125.8 8.6 93 90 90 01/30/18 SW Building A 391 4 0 134.9 7.4 126.9 8.6 94 90 91 01 /3 1/18 s Building A 392 4 0 134.9 7.4 119.9 4.9 89 90 91 A 01 /31/18 s Building A 392 4 0 134.9 7.4 125.3 8.7 93 90 92 02/0 l /18 Driveway F 381 16 0 130.7 8.2 116.3 4.2 89 90 92 A 02/01/18 Driveway F 381 16 0 130.7 8.2 122.2 9.3 93 90 93 02/0 I /18 Driveway F 384 16 20 136.4 6.6 128.7 8.1 94 90 94 02/02/18 Driveway E 378 16 10 133 .5 7.4 122.8 9.0 92 90 95 02/02/18 Driveway E 376 16 20 136.4 6.6 126.4 8.2 93 90 96 02/05/18 SE Corner Site Basin 362 16 20 136.4 6.6 120.0 3.6 88 90 96 A 02/05/18 SE Corner Site Basin 362 16 20 136.4 6.6 126.7 7.8 93 90 97 02/05/18 SE Site Cut Slope 367 16 20 136.4 6.6 113.6 5.8 83 90 98 02/06/18 E Driveway F 384 16 10 133.5 7.4 126.9 9.0 95 90 99 02/06/18 w Driveway F 386 16 10 133.5 7.4 125.2 8.7 94 90 -l-00 R Ot)O':f.,ll 8 8e GerneF eff B1:1ileing G ~ ¼ -1-0 ~ M ++&+ ~ && 90 -W+ R O:UQ1,ll8 8e GemeF eff Buileing G ~ ¼ w +.¼.-4 &.6 +;!-1-;4 ~ &9 90 102 02/07/18 SE Corner off Building C 374 16 20 136.4 6.6 126.7 7.9 93 90 103 02/07/18 SE Corner off Building C 374 16 20 136.4 6.6 128.1 8.3 94 90 104 02/08/18 Driveway E 377 16 10 133.5 7.4 125.0 8.6 94 90 105 02/08/18 SE off Building C 378 16 10 133.5 7.4 124.5 9.1 93 90 106 02/08/18 Driveway E 379 16 10 133.5 7.4 125.2 9.0 94 90 107 02/09/18 Driveway E 376 16 20 136.4 6.6 126.1 7.9 92 90 108 02/09/18 Driveway E 378 16 10 133.5 7.4 124.2 8.8 93 90 109 02/09/18 SE Corner off Building C 380 16 10 133.5 7.4 122.9 8.7 92 90 110 02/09/18 SE Corner off Building C 382 16 0 130.7 8.2 120.5 9.6 92 90 111 02/15/18 Driveway E Basin 379 16 0 130.7 8.2 127.1 8.8 97 90 112 02/15/18 Driveway E Utility OX 382 16 0 130.7 8.2 127.4 8.5 97 90 ~ G E OCO TABLE 1 SUMMARY OF FIELD DENSITY TEST RES UL TS Project Name: Pacific Vista Commerce Center (PVCC) Project No.: 06442-32-28A Elev. >¾" Max. Opt. Field Field Relative Required Date Test No. or Curve Dry Moist Dry Moisture Relative (MM/DD Location Rock Compaction /YY) Depth No. (%) Density Content Density Content (%) Compaction Pre. No. Re. (feet) (pcf) (%) (pct) (%) (%) I 13 02/15/18 Driveway C Utility OX 384 16 0 130.7 8.2 128.2 8.9 98 90 114 02/15/18 w Building C Loading Dock 385 16 20 136.4 6.6 127.2 7.8 93 90 115 02/20/18 SE Driveway F 370 16 20 136.4 6.6 128.2 8.4 94 90 116 02/2 0/18 SE Driveway F 371 16 10 133.5 7.4 124.8 9.1 93 90 117 02/21/18 Driveway F 375 16 0 130.7 8.2 123.3 9.3 94 90 118 02/2 1118 Driveway F 373 16 20 136.4 6.6 126.8 8.0 93 90 I 19 02/21/18 SE Building A 393 16 10 133.5 7.4 122.6 8.9 92 90 120 02/2 1/18 Landscape btwn Buildings A&B 390 16 10 133.5 7.4 125 .1 8.6 94 90 121 02/21/18 W Edge Landscape 394 16 20 136.4 6.6 122.1 8.7 90 90 ~ R Q;!,l;Q,il8 g 9Five,.,,,a)' I< Pill 81epe J++ M +o ~ +4 -1-++-e ~ 84 -9(} ~ R Q;!,12;!,il8 g t>Fiveway F Fill 8lepe ~ M +o ~ +4 -I-OU li &--1---9(} 124 02/22/18 SE Driveway F Fill Slope 362 16 0 130.7 8.2 121.7 9.3 93 90 FG 125 02/23/18 SE Building A 394 16 20 136.4 6.6 130.4 7.9 96 90 FG 126 02/23/18 SE Building A 395 16 20 136.4 6.6 129.0 7.8 95 90 FG 127 02/23/18 NW Building A 395 16 0 130.7 8.2 124.8 9.4 95 90 ~GE OCON AC Asphalt Concrete AD Area Drain B Base CG Curb/Gutter DW Driveway ET Electrical Trench ETB Exploratory Trench FB Footing Backfill FG Finish Grade FS Fire Service GT Gas Trench TABLE 1 EXPLANATION OF CODED TERMS TEST NO. PREFIX IT Irrigation Trench JT Joint Trench M Moisture Test MG Minor Grading MSE Mechanically Stabilized Earth Wall PT Plumbing Trench RG Regrade RWL Reclaimed Water Lateral RWM Reclaimed Water Main SBT Subdrain Trench SD Storm Drain TEST NO. RE. SG Subgrade SL Sewer Lateral SM Sewer Main SR Slope Repair ST Slope Test SW Sidewalk sz Slope Zone UT Utility Trench WB Wall Backfill WL Water Lateral WM Water Main A, B,C, ... I Retest of previous density test failure following additional moisture conditioning or recompaction R I Fill in area of density test was removed during construction operations ELEV A TION OR DEPTH Corresponds to the elevation or the depth, in feet, of the in-place density/moisture content test. The value has been rounded to the nearest whole foot CURVE NO. Corresponds to the curve numbers presented in the summary of the laboratory maximum dry density and optimum moisture content test results. The field representative selected the curve no. based on the laboratory test results and field observations >¾" ROCK -ROCK CORRECTION The laboratory maximum dry density and optimum moisture content can be adjusted for in-place soil that possesses rock larger than¾ inch. The curve no. is adjusted for the percentage of¾ inch rock in accordance with ASTM D 4718 or Woodward Clyde guidelines. Proctor Curve No. 4 12 13 16 Sample No. EI-3 TABLE II SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS ASTM D 1557 Maximum Source and Description Dry Density (pct) Dark reddish brown, Silty fine SAND 134.9 Brown Silty, fine to course SAND 132.5 Dark brown, Silty, fine to coarse SAND 135 .7 Dark yellow brown silty (f-c) SAND 130.7 TABLE Ill SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS ASTM D 4829 Moisture Content Dry Density Before Test(%) After Test(%) (pct) 7.1 13.4 121.0 TABLE IV Optimum Moisture Content(%) 7.4 9.8 7.4 8.2 Expansion Index 0 SUMMARY OF LABORATORY WATER-SOLUBLE SULFATE TEST RESULTS CALIFORNIA TEST NO. 417 Sample No. Water-Soluble Sulfate(%) Sulfate Exposure EI-3 0.003 Not Applicable TABLE V SUMMARY OF FINISH GRADE EXPANSION INDEX AND SULFATE EXPOSURE TEST RESULTS, AND RECOMMENDED FOUNDATION CATEGORY Building Sample at Expansion CBC Recommended Sulfate Expansion Foundation Number Finish Grade Index Classification Category Exposure A EI-3 0 Very Low I Not Applicable Project No. 06442-32-28A March 8, 201 8